Patent EP-2221138-A1 (EP)
Inventor: HILDEBRAND ALEXANDER DIPL-ING
IPC: B23K26/08
Filed: 2010-01-15
Abstract: The method comprises coupling a laser beam (17) into the semiconductor crystal (11), focusing the laser beam in a given depth in the semiconductor crystal in a focus (18), producing a vulnerability through the laser beam in the area of the focus in the semiconductor crystal, and producing number of differently positioned vulnerability in a separation plain (13) for removing the semiconductor wafer (12) from the semiconductor crystal. The laser beam is coupled in the semiconductor crystal by a light coupling means for increasing the numeric aperture and/or for reducing reflection losses. The method comprises coupling a laser beam (17) into the semiconductor crystal (11), focusing the laser beam in a given depth in the semiconductor crystal in a focus (18), producing a vulnerability through the laser beam in the area of the focus in the semiconductor crystal, and producing number of differently positioned vulnerability in a separation plain (13) for removing the semiconductor wafer (12) from the semiconductor crystal. The laser beam is coupled in the semiconductor crystal by a light coupling means for increasing the numeric aperture and/or for reducing reflection losses. An immersion fluid such as oil or water, and/or a film is used as light coupling means. The laser beam is coupled parallel or transverse to a surface normal of the detached semiconductor wafer and/or the separation plain through the removed semi-conductor wafer, and/or in the plain of the separation plain in the semiconductor crystal. An optic for directing and/or focusing the laser beam is superimposed on the light coupling means. A perforation is produced in a given separation plain for removing the semiconductor from the semiconductor crystal by the vulnerability. The semi-conductor wafer is removed along the perforation by further laser and/or cooling and/or heating from the semiconductor crystal. The vulnerability of the perforation is spirally or radially produced in the semiconductor crystal. The position and/or depth of the focus are adjusted within the semiconductor wafer to be detached and/or the semiconductor crystal for producing differently positioned vulnerability in freely selectable manner. The further vulnerability is produced for removing the semiconductor chip from the semiconductor wafer and/or for structuring and/or texturing the surface of the semiconductor crystals and/or semiconductor wafer. In-line-autofocus measurement and/or a suitable thickness of the film is used for changing and adjusting the depth of the focus in the semiconductor crystal and/or the semiconductor wafer to be detached. A carrier material is applied on the semiconductor wafer to be detached of the semiconductor crystal before and/or after coupling the laser beam. An adhesion foil or light coupling means is used as carrier material. The flexible semi-conductor is produced with a layer thickness of less than 10 mu m. The flexible semiconductor wafer is stripped off during coupling the laser beam in the plain of the separation plain in dependent upon the produced vulnerability gradually from the semiconductor crystal. An integrated circuit and/or an another component is partially subjected in the semi-conductor wafer before removing the semiconductor wafer and/or subjected on the semi-conductor wafer. An independent claim is included for a device for separating a thin and/or large-scale semiconductor wafer from a semiconductor crystal.